The mobile operator has announced it is moving to a new network infrastructure in the north-east of England, Northern Ireland and Scotland, boosting the speed and reliability of 3G voice and data services in those regions and smoothing the way for rollouts of the faster 3.5G technology before the end of next year.

Orange said the improvements will bring faster 3G data services along with a more reliable combined voice and data service, and a 99 percent call-connection success rate. Areas covered in the regions will include cities and towns, major roads, rail routes, business parks, conference centres, hotels and airports, the operator added.

Peter Marsden, vice president of IT and networks at Orange, said in a statement: "We are investing heavily to improve our network, and this investment is one step closer to our goal of becoming the best UK network for coverage and reliability by 2009."

Orange already lays claim to the largest integrated 3G/2.5G network in the UK, covering 99 percent of the UK population.

Orange said customers in the north-east of England, Northern Ireland and Scotland are likely to incur some 3G downtime but that any such outages will be fully communicated in advance and network engineers will attempt to ensure there is minimal disruption. Orange added that its 2G network will be available throughout, athough it said the changes will have "limited effect" on 2G access or voice calls.

In addition to improving 3G performance in the three regions, Orange said it will be rolling out a faster variant of 3G/HSDPA (also known as 3.5G) before the end of 2009 to better support mobile broadband.

Orange said it is working towards 3G/HSDPA network speed targets of up to 7.2Mbps in the top 30 UK cities; 2Mbps for 80 percent of the entire UK population; and will start rolling out 14.4Mbps by the end of 2009.

Orange added it will be installing more than 450 new 2G and 3G sites over the next 12 months and claimed it spends "more than £1m every working day" to develop its network.